1. Field of the Invention
The present invention relates to magnetic tape drive equipment. More particularly, the present invention relates to apparatus for extracting the tape from the cassette and guiding it into engagement with the tape heads which are used to read the information from the tape.
2. The Prior Art
Mechanisms for inserting and ejecting magnetic tape cassettes from the devices in Which they are utilized exist in the prior art. While these mechanisms often provide for the manual insertion of the tape cassette into the device, all of such mechanisms known to the inventors utilize a motor drive for the purpose of assisting in the insertion and ejection of the tape cassette from the device once it has finished running. In such mechanisms, a power failure in the device makes the extraction of the cassette from the device difficult or impossible.
In addition, any mechanism for inserting and ejecting the cassettes must take into account the height of the tape drive hub spindles (approximately 0.30") used in the device to drive the tape reels contained within the cassettes, since the cassette must clear them when it is both inserted and ejected. The presence of the tape drive hub spindles also requires that the vertical motion of the cassette during insertion and ejection be free from any degree of lateral motion or tilt which would act to bind the cassette on the hub spindles and thus impede its motion.
Devices equipped with helical-scan heads include tape correction pins which are used to correct the orientation of the tape from the tilted plane caused by its engagement with the helical-scan head drum assembly to the vertical plane associated with the cassette. In such devices in the prior art which are known to the inventors, these pins are usually located within the tape puller roller blocks which are used to bring the tape into contact with the helical-scan head drum assembly. Because these pins are placed on the moveable tape puller roller blocks, they are more or less prone to misalignment caused by improper registration of the blocks with the drum assembly.